3,888 research outputs found

    Conceptual studies on the integration of a nuclear reactor system to a manned rover for Mars missions

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    Multiyear civilian manned missions to explore the surface of Mars are thought by NASA to be possible early in the next century. Expeditions to Mars, as well as permanent bases, are envisioned to require enhanced piloted vehicles to conduct science and exploration activities. Piloted rovers, with 30 kWe user net power (for drilling, sampling and sample analysis, onboard computer and computer instrumentation, vehicle thermal management, and astronaut life support systems) in addition to mobility are being considered. The rover design, for this study, included a four car train type vehicle complete with a hybrid solar photovoltaic/regenerative fuel cell auxiliary power system (APS). This system was designed to power the primary control vehicle. The APS supplies life support power for four astronauts and a limited degree of mobility allowing the primary control vehicle to limp back to either a permanent base or an accent vehicle. The results showed that the APS described above, with a mass of 667 kg, was sufficient to provide live support power and a top speed of five km/h for 6 hours per day. It was also seen that the factors that had the largest effect on the APS mass were the life support power, the number of astronauts, and the PV cell efficiency. The topics covered include: (1) power system options; (2) rover layout and design; (3) parametric analysis of total mass and power requirements for a manned Mars rover; (4) radiation shield design; and (5) energy conversion systems

    Changes in Cognition over a 16.1 km Cycling Time Trial using Think Aloud Protocol: Preliminary Evidence.

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    Objectives: This study investigated cognitions of cyclists during a competitive time trial (TT) event using Think Aloud (TA) protocol analysis. Design: Single group, observational design. Method: Fifteen male and three female cyclists from the North West of England verbalised their thoughts throughout an outdoor competitive 16.1 km cycling time trial (Level 2 TA). Verbalisations were recorded using iVue Horizon 1080P camera glasses. Data was transcribed verbatim, analysed using deductive content analysis and grouped into themes: (i) Pain And Discomfort (Fatigue, Pain), (ii) External Feedback (Time, Speed, Heart Rate), (iii) Environment (Surroundings, Traffic and Other Cyclists), (iv) Pace and Distance (Pace, Distance). The number of verbalisations within each theme were analysed by distance quartile using Friedman tests to examine changes in cognitions over time. Results: Associative themes, including Fatigue and Pain, were verbalised more frequently in the earlier stages of the TT and less in the final quartile, whereas verbalisations about Distance significantly increased in the last quartile. Conclusions: This study demonstrates how a novel data collection method can capture in-event cognitions of endurance athletes. It provides an important extension to previous literature, showing how individuals may process and attend to information over time during an exercise bout. Future research should establish the relationship between performance and cognitive processes

    WhoLoDancE: Towards a methodology for selecting Motion Capture Data across different Dance Learning Practice

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    <p>In this paper we present the objectives and preliminary work of WhoLoDancE a Research and Innovation Action funded under the European Union‘s Horizon 2020 programme, aiming at using new technologies for capturing and analyzing dance movement to facilitate whole-body interaction learning experiences for a variety of dance genres. Dance is a diverse and heterogeneous practice and WhoLoDancE will develop a protocol for the creation and/or selection of dance sequences drawn from different dance styles for different teaching and learning modalities. As dance learning practice lacks standardization beyond dance genres and specific schools and techniques, one of the first project challenges is to bring together a variety of dance genres and teaching practices and work towards a methodology for selecting the appropriate shots for motion capturing, to acquire kinetic material which will provide a satisfying proof of concept for Learning scenarios of particular genres. The four use cases we are investigating are 1) classical ballet, 2) contemporary dance, 3) flamenco and 4) Greek folk dance.</p

    Synthesis, crystal structure, physical and catalytic oxidation studies of a new hybrid phosphate [(N2H5)2Co(HPO4)2]

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    A new one-dimensional coordination polymer [(N2H5)2Co(HPO4)2] was synthesized by slow evaporation method and characterized by means of single-crystal X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Its catalytic activity was tested using UV–visible absorption measurements. The compound crystallizes in the monoclinic system (S.G: P21/c) with the cell parameters (Å, °): a = 5.3665(3), b = 11.1271(6), c = 7.7017(4), β = 104.843(4), V = 444.55(4) Å3 and Z = 2. The crystal structure, consisting of a linear chain, is made of rings of [CoN2O4] octahedra and [PO3(OH)] tetrahedra sharing vertices via oxygen atoms coordinated to cobalt centers. The rings are linked to chains running along [100] and form thereby polymeric chains that are connected by hydrogen bonds in a three-dimensional arrangement. The FTIR spectroscopy shows the expected bands of hydrazine and phosphate groups. The thermal behavior consists mainly of the loss of hydrazine moieties leading thus to the formation of anhydrous cobalt phosphate. The phosphate complex exhibits efficiency in catalytic oxidation and degradation of methylene blue dye. The ac magnetic susceptibility shows a peak indicating antiferromagnetic order with a Néel temperature of 5.5 K. Fitting the Curie-Weiss equation to the ac magnetic susceptibility above 50 K gives the average Curie-Weiss Constant to be −11.8 K

    Protocol for the development of guidance for stakeholder engagement in health and healthcare guideline development and implementation

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    Stakeholder engagement has become widely accepted as a necessary component of guideline development and implementation. While frameworks for developing guidelines express the need for those potentially affected by guideline recommendations to be involved in their development, there is a lack of consensus on how this should be done in practice. Further, there is a lack of guidance on how to equitably and meaningfully engage multiple stakeholders. We aim to develop guidance for the meaningful and equitable engagement of multiple stakeholders in guideline development and implementation. METHODS: This will be a multi-stage project. The first stage is to conduct a series of four systematic reviews. These will (1) describe existing guidance and methods for stakeholder engagement in guideline development and implementation, (2) characterize barriers and facilitators to stakeholder engagement in guideline development and implementation, (3) explore the impact of stakeholder engagement on guideline development and implementation, and (4) identify issues related to conflicts of interest when engaging multiple stakeholders in guideline development and implementation. DISCUSSION: We will collaborate with our multiple and diverse stakeholders to develop guidance for multi-stakeholder engagement in guideline development and implementation. We will use the results of the systematic reviews to develop a candidate list of draft guidance recommendations and will seek broad feedback on the draft guidance via an online survey of guideline developers and external stakeholders. An invited group of representatives from all stakeholder groups will discuss the results of the survey at a consensus meeting which will inform the development of the final guidance papers. Our overall goal is to improve the development of guidelines through meaningful and equitable multi-stakeholder engagement, and subsequently to improve health outcomes and reduce inequities in health

    Is nutrition important to postpone frailty?

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    Purpose of review: The purpose of the present study is to provide an updated, systematic review of the recent literature on whether nutrition is important to postpone frailty. Recent findings: A systematic review of recent literature (past 12 months) identified nine studies (eight of which using a cross-sectional design) exploring the relationship between nutrition and frailty. A single randomized-controlled double-blind trial was published. However, being a pilot study, it was characterized by a relatively small sample size, short follow-up length (i.e., 6 months), and low statistical power. Notably, available evidence shows considerable variability in participants’ selection and assessment methods, rendering difficult direct comparisons. Size effects or magnitude of associations across the different studies cannot also be determined. Summary: There is a need for long-term, adequately powered, randomized controlled trials examining nutrition (alone or/and in combination with other appropriate interventions) as a means for postponing frailty in older persons

    Hyperthyroidism and human chorionic gonadotrophin production in gestational trophoblastic disease

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    Background: Gestational trophoblastic disease (GTD) is a rare complication of pregnancy, ranging from molar pregnancy to choriocarcinoma. Patients with persistent disease require treatment with chemotherapy. For the vast majority, prognosis is excellent. Occasionally, GTD is complicated by hyperthyroidism, which may require treatment. This is thought to occur due to molecular mimicry between human chorionic gonadotrophin (HCG) and thyroid-stimulating hormone (TSH), and hence cross-reactivity with the TSH receptor. Hyperthyroidism usually resolves as the GTD is successfully treated and correspondingly HCG levels normalise. Methods: This paper reviews cases of GTD treated over a 5-year period at one of the three UK centres and identifies the prevalence of hyperthyroidism in this population. Four cases with clinical hyperthyroidism are discussed. Results: On review of the 196 patients with gestational trophoblastic neoplasia treated with chemotherapy in Sheffield since 2005, 14 (7%) had biochemical hyperthyroidism. Of these, four had evidence of clinical hyperthyroidism. Conclusion: Concomitant biochemical thyroid disease in patients with GTD is relatively common, and measurement of thyroid function in patients with persistent GTD is, therefore, important. The development of hyperthyroidism is largely influenced by the level of HCG and disease burden, and usually settles with treatment of the persistent GTD. However, rarely the thyroid stimulation can have potentially life-threatening consequences
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